• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.743-746
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• 2003

The major pathological lesion in Parkinson's disease(PD) is selective degeneration and loss of pigmented dopaminergic neurons in substantia nigra (SN). Although the initial cause and subsequent molecular signaling mechanisms leading to the dopaminergic cell death underlying the PD process is elusive, the potent neurotrophic factors (NTFs), brain derived neurotrophic factor (BDNF) and glial cell line derived neurotrophic factor (GDNF), are known to exert dopaminergic neuroprotection both in vivo and in vitro models of PD employing the neurotoxin, MPTP. BDNF and its receptor, trkB are expressed in SN dopaminergic neurons and their innervation target. Thus, neurotrophins may have autocrine, paracrine and retrograde transport effects on the SN dopaminergic neurons. This study determined the BDNF secretion from SN dopaminergic neurons by ELISA. Regulation of BDNF synthesis/release and changes in signaling pathways are monitored in the presence of free radical donor, NO donor and mitochondrial inhibitors. Also, this study shows that BDNF is able to promote survival and phenotypic differentiation of SN dopaminergic neurons in culture and protect them against MPTP-induced neurotoxicity via MAP kinase pathway.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.130.3-131
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• 2003

Inflammation is a frequent radiation-induced following therapeutic irradiation. Since the upregulation of adhesion molecules on endothelial cell surface has been known to be associated with inflammation, interfering with the expression of adhesion molecules is an important therapeutic target. We examined the effect if allicin, a major component of garlic, on the induction of intercellular adhesion molecule-l (ICAM-1) by gamma-irradiation and the mechanisms of its effect in gamma-irradiated human umbilical vein endothelial cells (HUVECs). (omitted)

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.307.1-307.1
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• 2002

Inflammation is a frequent radiation-induced following therapeutic irradiation. Since the upregulation of adhesion molecules on endothelial cell surface has been known to be associated with inflammation. interfering with the expression of adhesion molecules is an important therapeutic target. We examined the effect of allicin. a major component of garlic. on the induction of intercellular adhesion molecule-1 (lCAM-1) by gamma-irradiation and the mechanisms of its effect in gamma-irradiated human umbilical vein endothelial cells (HUVECs). (omitted)

• Journal of Life Science
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• v.30 no.4
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• pp.331-342
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• 2020

The suppression of neuroinflammatory responses in microglial cells can be considered a key target for improving the progression of neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). Asparagus cochinchinensis has traditionally been used as a medicine to treat fever, cough, kidney disease, breast cancer, inflammatory diseases, and brain diseases. In this study, we investigated the neuroprotective mechanism of an aqueous extract from A. cochinchinensis root (AEAC), particularly its anti-inflammatory effects on lipopolysaccharide (LPS)-activated BV-2 microglial cells. BV-2 cells were treated with four different concentrations of AEAC. No significant toxicity was detected in BV-2 cells treated with AEAC. Nitric oxide (NO), cyclooxygenase-2 (COX-2) mRNA, and inducible nitric oxide synthase (iNOS) mRNA levels were 21% lower in the AEAC+LPS group than in the Vehicle+LPS group. Lower proinflammatory (TNF-α and IL-1β) and anti-inflammatory cytokine (IL-6 and IL-10) levels were also detected in the AEAC+LPS group than in the Vehicle+LPS group, albeit at varying rates. Moreover, the phosphorylation of mitogen-activated protein kinase (MAPK) members after LPS treatment was significantly recovered in the AEAC-pretreated group compared to the Vehicle+LPS group, enhancement of the phosphorylation of mitogen-activated protein kinase (MAPK) members after LPS treatment was significantly recovered in the AEAC-pretreated group, while cell cycle arrest at the G2/M phase caused by LPS treatment was less severe in the AEAC+LPS group. The increase in reactive oxygen species (ROS) generation induced by LPS treatment was also lower in the AEAC-pretreated group than in the Vehicle+LPS group. This is the first study to show that AEAC exerts anti-neuroinflammatory activity against LPS stimulation by regulating the MAPK signaling pathway, the cell cycle, and ROS production.

• BMB Reports
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• v.33 no.6
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• pp.525-530
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• 2000

The nerve growth factor (NGF) induces neuronal differentiation and neurite outgrowth of PC12 cells, whereas epidermal growth factors (EGF) stimulate growth and proliferation of the cells. In spite of this difference, NGF-or EGF-treated PC12 cells share various properties in cellular-signaling pathways. These include the activation of the phosphoinositide (PI)-3 kinase, 70 kDa S6 kinase, and in the mitogen-activated protein (MAP) kinase pathway, following the binding of these growth factors to intrinsic receptor tyrosine kinases (RTKs). Therefore, many studies have been attempted to access the critical signaling events in determining the differentiation and proliferation of PC12 cells. In this study, we investigated the cytosolic phospholipase $A_2$ ($cPLA_2$) in neurite behavior in order to identify the differences of signaling pathways between the NGF-induced differentiation and the EGF-induced proliferation of PC12 cells. We have showed here that the $cPLA_2$ was translocated from cytosol to membrane only in NGF-treated cells. We also demonstrated that this translocation is associated with NGF-induced activation of phospholipase $C-{\gamma}(PLC-{\gamma})$, which elevates intracellular $Ca^{2+}$ concentration. These results reveal that the translocation of $cPLA_2$ may be a requisite event in the neuronal differentiation of PC12 cells. Various phospholipase inhibitors were used to confirm the importance of these enzymes in the differentiation of PC12 cells. Neomycin B, a PLC inhibitor, dramatically inhibited the neurite outgrowth, and two distinct $PLA_2$ inhibitors, 4-bromophenacyl bromide (BPB) and arachidonyltrifluoro-methyl ketone ($AACOCF_3$) also suppressed the neurite outgrowth of the cells, as well Taken together, these data indicated that $cPLA_2$ is involved in NGF-induced neuronal differentiation and neurite outgrowth of PC12 cells.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.113-113
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• 2002

The stimulatory effect of EGF and FSH on oocyte maturation have been reported in various mammalian species. And some reports presented FSH enhanced the effect of EGF on oocyte maturation. But, the interaction between EGF and FSH on nuclear maturation of mammalian oocytes is not fully understood. We observed the effect of EGF and FSH on nuclear maturation during in vitro maturation of mouse oocytes. Also, we examined the interaction between EGF and FSH on nuclear maturation of mouse oocytes using the EGFR inhibitor or FSH inhibitor. Germinal vesicle (GV) stage oocytes were obtained from 3-4weeks PMSG primed BCFI hybrid mice and cultured in TCM-199 medium with 0.4%PVP supplemented with/without EGF (1ng/ml), FSH (1ug/ml), EGFR specific tyrosine kinase inhibitors: Tyrphostin AG 1478 (500nM), MAP kinase kinase inhibitor : U0126 (20uM) or PD 98059 (100uM) for 14-l5hr. Rapid staining method were used for the assessment of nuclear maturation. Nuclear maturation rates of EGF indjor FSH-treated group were significantly higher than those of control group. Treatment of EGFR inhibitor significantly block the nuclear maturation of GV oocyte in EGF-treated group, but it did not block those of GV oocyte in FSH-treated or FSH and EGF-treated group. Treatment of FSH inhibitor(U0126, PD98059) significantly block the nuclear maturation of EGF-treated group, FSH-treated and FSH and EGF-treated group. These results show that EGF has a stimulatory effect as well as different action pathway with FSH on in-vitro maturation of mouse oocyte in vitro. Therefore, further studies will be needed to find the signaling pathway of EGF associated with nuclear maturation.

• Proceedings of the Microbiological Society of Korea Conference
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• 2007.05a
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• pp.120-122
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• 2007

All living organisms use numerous signal-transduction pathways to sense and respond to their environments and thereby survive and proliferate in a range of biological niches. Molecular dissection of these signalling networks has increased our understanding of these communication processes and provides a platform for therapeutic intervention when these pathways malfunction in disease states, including infection. Owing to the expanding availability of sequenced genomes, a wealth of genetic and molecular tools and the conservation of signalling networks, members of the fungal kingdom serve as excellent model systems for more complex, multicellular organisms. Here, we employed Cryptococcus neoformans as a model system to understand how fungal-signalling circuits operate at the molecular level to sense and respond to a plethora of environmental stresses, including osmoticshock, UV, high temperature, oxidative stress and toxic drugs/metabolites. The stress-activated p38/Hog1 MAPK pathway is structurally conserved in many organisms as diverse as yeast and mammals, but its regulation is uniquely specialized in a majority of clinical Cryptococcus neoformans serotype A and D strains to control differentiation and virulence factor regulation. C. neoformans Hog1 MAPK is controlled by Pbs2 MAPK kinase (MAPKK). The Pbs2-Hog1 MAPK cascade is controlled by the fungal "two-component" system that is composed of a response regulator, Ssk1, and multiple sensor kinases, including two-component.like (Tco) 1 and Tco2. Tco1 and Tco2 play shared and distinct roles in stress responses and drug sensitivity through the Hog1 MAPK system. Furthermore, each sensor kinase mediates unique cellular functions for virulence and morphological differentiation. We also identified and characterized the Ssk2 MAPKKK upstream of the MAPKK Pbs2 and the MAPK Hog1 in C. neoformans. The SSK2 gene was identified as a potential component responsible for differential Hog1 regulation between the serotype D sibling f1 strains B3501 and B3502 through comparative analysis of their meiotic map with the meiotic segregation of Hog1-dependent sensitivity to the fungicide fludioxonil. Ssk2 is the only polymorphic component in the Hog1 MAPK module, including two coding sequence changes between the SSK2 alleles in B3501 and B3502 strains. To further support this finding, the SSK2 allele exchange completely swapped Hog1-related phenotypes between B3501 and B3502 strains. In the serotype A strain H99, disruption of the SSK2 gene dramatically enhanced capsule biosynthesis and mating efficiency, similar to pbs2 and hog1 mutations. Furthermore, ssk2, pbs2, and hog1 mutants are all hypersensitive to a variety of stresses and completely resistant to fludioxonil. Taken together, these findings indicate that Ssk2 is the critical interface protein connecting the two-component system and the Pbs2-Hog1 pathway in C. neoformans.

• Journal of Life Science
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• v.22 no.9
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• pp.1137-1144
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• 2012

Inflammation is a host defense mechanism that is activated in response to harmful substances or pathogens. However, an excessive inflammatory response is a problem in itself. Macrophages secrete inflammatory mediators such as nitric oxide (NO) or cytokines through various pathways such as the nuclear factor kappa B (NF-${\kappa}B$)-activated pathway after recognizing pathogen-like lipopolysaccharides (LPSs). In this study, anti-inflammatory effects of Eupatorium chinensis var. simplicifolium (EUC) extracts were investigated using LPS-stimulated RAW 264.7 macrophages. The EUC root extract significantly reduced NO production, inducible nitric oxide synthase (iNOS) expression, and cyclooxygenase-2 expression in a concentration-dependent manner. In addition, the EUC root extract reduced phosphorylation of mitogen-activated protein kinases and protein kinase B, which is upstream of NF-${\kappa}B$. The EUC root extract also reduced the degradation of inhibitory kappa B. These results indicate that EUC root extract exerts anti-inflammatory effects, which are mediated by inhibition of iNOS expression and the NF-${\kappa}B$ pathway.

• Journal of Applied Biological Chemistry
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• v.62 no.1
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• pp.39-50
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• 2019

Mitogen-activated protein (MAP) kinases play an important role in cell growth and differentiation, as well as the modulation of proinflammatory cytokines. The objective of this study was to examine the increase in the anti-inflammatory effect of Gentiana scabra Bunge (GSB), due to bioconversion with the Aspergillus kawachii crude enzyme, via inhibition of the $NF-{\kappa}B$ signaling and MAP kinase pathways in RAW 264.7 cells. The expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 in RAW 264.7 cells treated with the GSB ethyl acetate fraction bioconverted with A. kawachii crude enzyme (GE-BA), was dramatically suppressed as compared to GSB ethyl acetate fraction non-bioconverted with the A. kawachii crude enzyme (GE-UA). The phosphorylation of p38, extracellular signal-regulated kinases, and inhibitory ${\kappa}B$ in RAW 264.7 cells treated with GE-BA was further suppressed, as compared to exposure to GE-UA. Moreover, the mRNA expression of interleukin 6, interleukin 1-beta, and tumor necrosis $factor-{\alpha}$ was further suppressed by GE-BA, compared to GE-UA. Similarly, anti-oxidant activities, such as 2,2-diphenyl-1-picrylhydrazyl hydrate and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activity, of GE-BA were further increased compared to GE-UA. These observations demonstrate that the anti-oxidant and anti-inflammatory activities of GSB ethyl acetate fraction increases as a result from bioconversion with the A. kawachii crude enzyme.

• Korean Journal of Biological Psychiatry
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• v.20 no.4
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• pp.159-165
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• 2013

Objectives Mechanisms of clinical synergistic effects, induced by co-treatments of lithium and valproate, are unclear. Extracellular signal-regulated kinase (ERK) has been suggested to play important roles in mechanisms of the action of mood stabilizers. In this study, effects of co-treatments of lithium and valproate on the ERK1/2 signal pathway and its down-stream transcription factors, ELK1 and C-FOS, were investigated in vitro. Methods PC12 cells, human pheochromocytoma cells, were treated with lithium chloride (30 mM), valproate (1 mM) or lithium chloride + valproate. The phosphorylation of ERK1/2 was analyzed with immunoblot analysis. Transcriptional activities of ELK1 and C-FOS were analyzed with reporter gene assay. Results Single treatment of lithium and valproate increased the phosphorylation of ERK and transcriptional activities of ELK1 and C-FOS, respectively. Combined treatments of lithium and valproate induced more robust increase in the phosphorylation of ERK1/2 and transcriptional activities of ELK1 and C-FOS, compared to those in response to single treatment of lithium or valproate. Conclusions Co-treatments of lithium and valproate induced synergistic increase in the phosphorylation of ERK1/2 and transcriptional activities of its down-stream transcription factors, ELK1 and C-FOS, compared to effects of single treatment. The findings might suggest potentiating effects of lithium and valproate augmentation treatment strategy.